108 research outputs found

    Planilha eletrônica para o cálculo da reflectância em imagens TM e ETM+ LANDSAT.

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    A reflectância de culturas agrícolas e de outros alvos da superfície terrestre é um parâmetro intrínseco dos objetos sensoriados e, assim, em muitas situações, deve ser utilizada em lugar dos valores de níveis de cinza normalmente encontrados nas imagens de satélite. Para obter a reflectância de alvos de imagens de satélite é necessário eliminar a interferência atmosférica e realizar uma série de cálculos que envolvem parâmetros do sensor e informações da própria imagem. Automatizar esse procedimento tem como vantagens a agilização do processo e a redução dos riscos de erros durante os cálculos. O objetivo do presente artigo é apresentar uma planilha eletrônica que simplifica e automatiza a transformação dos números digitais das imagens TM e ETM+ dos satélites Landsat 5 e 7 em valores de reflectância, isto é, um parâmetro intrínseco dos objetos sensoriados e, portanto, com significado físico. O método de correção atmosférica empregado é o da subtração de objeto escuro ou DOS. A planilha eletrônica aqui descrita pode ser encontrada no endereço eletrônico http://www.dsr.inpe.br/Calculo_Reflectancia.xls e pode ser utilizada para calcular valores de reflectância em imagens dos sensores Landsat TM e ETM+

    Targeting Neutrophils to Prevent Malaria-Associated Acute Lung Injury/Acute Respiratory Distress Syndrome in Mice

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    Malaria remains one of the greatest burdens to global health, causing nearly 500,000 deaths in 2014. When manifesting in the lungs, severe malaria causes acute lung injury/acute respiratory distress syndrome (ALI/ARDS). We have previously shown that a proportion of DBA/2 mice infected with Plasmodium berghei ANKA (PbA) develop ALI/ARDS and that these mice recapitulate various aspects of the human syndrome, such as pulmonary edema, hemorrhaging, pleural effusion and hypoxemia. Herein, we investigated the role of neutrophils in the pathogenesis of malaria-associated ALI/ARDS. Mice developing ALI/ARDS showed greater neutrophil accumulation in the lungs compared with mice that did not develop pulmonary complications. In addition, mice with ALI/ARDS produced more neutrophil-attracting chemokines, myeloperoxidase and reactive oxygen species. We also observed that the parasites Plasmodium falciparum and PbA induced the formation of neutrophil extracellular traps (NETs) ex vivo, which were associated with inflammation and tissue injury. The depletion of neutrophils, treatment with AMD3100 (a CXCR4 antagonist), Pulmozyme (human recombinant DNase) or Sivelestat (inhibitor of neutrophil elastase) decreased the development of malaria-associated ALI/ARDS and significantly increased mouse survival. This study implicates neutrophils and NETs in the genesis of experimentally induced malaria-associated ALI/ARDS and proposes a new therapeutic approach to improve the prognosis of severe malaria

    Infection by Toxoplasma gondii in Neotropical non-human primates

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    Toxoplasma gondii (Nicolle et Manceaux, 1909) is an obligatory intracellular protozoan parasite of warm animals, including human and non-human primates. Domestic and wild felids are considered definitive hosts. Several authors have already identified lesions in New World primates caused by T. gondii. Nevertheless, little is known about serological studies on those animals. With this reason, New World non-human primates of the genera Cebus and Callithrix that were apprehended by governmental authorities and sent to the Wildlife Screening Center (Cetas)/IBAMA, at the municipality of Seropédica, state of Rio Janeiro, were bled and sera were submitted to the indirect hemagglutination test for detection of anti-T. gondii antibodies. From 21 sera of Cebus primates, 76.19% (16/21) had anti-T. gondii antibodies. Titles varied from 16 to 2048. In samples from 21 Callithrix, only 4.5% (1/22) had anti-T. gondii antibodies. Only one animal had a title of 32. During all the time those animals were clinical evaluated until sample was collected; none of them had any clinical sign or sequel related to infection by T. gondii. The fact that the origin of these primates is unknown and that there is no information about their feeding habits before captivity makes it difficult to determine the source of T. gondii infection

    Predictive Criteria to Study the Pathogenesis of Malaria-Associated ALI/ARDS in Mice

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    Malaria-associated acute lung injury/acute respiratory distress syndrome (ALI/ARDS) often results in morbidity and mortality. Murine models to study malaria-associated ALI/ARDS have been described; we still lack a method of distinguishing which mice will develop ALI/ARDS before death. This work aimed to characterize malaria-associated ALI/ARDS in a murine model and to demonstrate the first method to predict whether mice are suffering from ALI/ARDS before death. DBA/2 mice infected with Plasmodium berghei ANKA developing ALI/ARDS or hyperparasitemia (HP) were compared using histopathology, PaO2 measurement, pulmonary X-ray, breathing capacity, lung permeability, and serum vascular endothelial growth factor (VEGF) levels according to either the day of death or the suggested predictive criteria. We proposed a model to predict malaria-associated ALI/ARDS using breathing patterns (enhanced pause and frequency respiration) and parasitemia as predictive criteria from mice whose cause of death was known to retrospectively diagnose the sacrificed mice as likely to die of ALI/ARDS as early as 7 days after infection. Using this method, we showed increased VEGF levels and increased lung permeability in mice predicted to die of ALI/ARDS. This proposed method for accurately identifying mice suffering from ALI/ARDS before death will enable the use of this model to study the pathogenesis of this disease.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ São Paulo, Inst Ciencias Biomed, Dept Imunol, BR-05508900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Ciencias Biol, BR-09972270 Diadema, SP, BrazilUniv São Paulo, Inst Med Trop São Paulo, BR-05403000 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Ciencias Exatas & Terra, BR-09972270 Diadema, SP, BrazilUniv São Paulo, Inst Ciencias Biomed, Dept Parasitol, BR-05508000 São Paulo, BrazilUniv São Paulo, Fac Med Vet & Zootecn, Dept Cirurgia, BR-05508270 São Paulo, BrazilUniv São Paulo, Fac Med Vet & Zootecn, Dept Med Vet Prevent & Saude Anim, BR-05508270 São Paulo, BrazilUniv São Paulo, Fac Ciencias Farmaceut, Dept Anal Clin & Toxicol, BR-05508000 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Ciencias Biol, BR-09972270 Diadema, SP, BrazilUniversidade Federal de São Paulo, Dept Ciencias Exatas & Terra, BR-09972270 Diadema, SP, BrazilFAPESP: 2009/53256-7FAPESP: 2009/53889-0CNPq: 306668/2012-2CNPq: 470590/2009-2Web of Scienc

    Caracterização espectral (400-2500 nm) de solos tropicais brasileiros.

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    No Brasil, há uma carência generalizada de informações espectrais sobre solos, sobretudo na faixa entre 400 e 2500 nm, quando se compara com o número de espectros de solos de regiões temperadas. Nesse contexto, ressalta-se que salvo recentes estudos realizados por Epiphanio et al. (1992), era praticamente nula a existência de curvas espectrais além de 1000 nm. Ou seja, há um descompasso entre a grande variabilidade dos solos brasileiros e o conhecimento sobre os seus respectivos comportamentos espectrais. Ademais, deve-se atentar para o fato de que existem, há algum tempo, sensores orbitais operando em faixas espectrais além de 1000 nm (por exemplo o TM/Landsat), e há previsões de lançamentos de novos sensores nestas faixas (Asrar e Dozier, 1994), inclusive o satélite CBERS (China Brazil Earth Resources Satellite). Adicionalmente, destaca-se, ainda, que o Brasil está entrando numa fase de desenvolvimento de seus próprios satélites de sensoriamento remoto. Atualmente, o CBERS está em fase adiantada de construção e em breve necessitará de experimentos de simulação e calibração. Da mesma forma, o Satélite de Sensoriamento Remoto da Missão Espacial Completa Brasileira (SSR/MECB) estará em órbita num tempo não muito distante. Assim, os objetivos do presente trabalho constaram de: a) determinar as curvas espectrais dos principais solos de algumas regiões brasileiras; b) identificar os principais parâmetros reguladores (intervenientes) do comportamento espectral dos solos estudados; c) caracterizar os solos nas diferentes faixas do espectro (visível, infravermelho próximo e infravermelho médio, compreendendo o intervalo entre 400 e 2500 nm), de acordo com suas respostas espectrais; e d) disponibilizar dados espectrais numa forma prontamente assimilável para a comunidade usuária

    The influence of high glucose conditions on macrophages and its effect on the autophagy pathway

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    IntroductionMacrophages are central cells in mediating the inflammatory response.Objective and MethodsWe evaluated the effect of high glucose conditions on the inflammatory profile and the autophagy pathway in Bone-Marrow Derived Macrophages (BMDM) from diabetic (D-BMDM) (alloxan: 60mg/kg, i.v.) and non-diabetic (ND-BMDM) C57BL/6 mice. BMDM were cultured in medium with normal glucose (5.5 mM), or high glucose (25 mM) concentration and were primed with Nigericin (20µM) stimulated with LPS (100 ng/mL) at times of 30 minutes; 2; 4; 6 and 24 hours, with the measurement of IL-6, IL-1β and TNF-α cytokines.ResultsWe have further identified changes in the secretion of pro-inflammatory cytokines IL-6, IL-1β and TNF-α, where BMDM showed increased secretion of these cytokines after LPS + Nigericin stimulation. In addition, changes were observed in the autophagy pathway, where the increase in the autophagic protein LC3b and Beclin-1 occurred by macrophages of non-diabetic animals in hyperglycemic medium, without LPS stimulation. D-BMDM showed a reduction on the expression of LC3b and Beclin-1, suggesting an impaired autophagic process in these cells.ConclusionThe results suggest that hyperglycemia alters the inflammatory pathways in macrophages stimulated by LPS, playing an important role in the inflammatory response of diabetic individuals
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